How Do I Find My IP Address In Mac OS X?
Go to the Apple menu on the top left of the screen in Mac OS X 10.6 and select System Preferences. Choose the Network panel then select AirPort (if you are connected wirelessly) or Ethernet to see your IP address.
Note: if you are connected to a local network this will only show your local IP address. If you are connected directly to a modem this will show your public IP address. If using a local network the easiest way to see your public IP address is to visit a service like What Is My IP Address?.